By Steve Schaefer Almost everyone was expecting a first-day pop from Facebook, and the social network's first trade was certainly in that direction. Shares opened at $42.05, up 10.7% from the $38 initial public offering price, then retreated back to the $40 neighborhood on a surge in volume right at the start of trading The first trade came more than 30 minutes later than the expected 11 a.m. open, and the Wall Street Journal reported traders had issues changing or cancelling orders. Facebook shares were sharply higher in the first few minutes of trading, after launching the biggest U.S. technology IPO in history after the closing bell Thursday, raising $16 billion at a $104 billion valuation, turning many employees into instant millionaires and boosting the net worth of billionaire founder Mark Zuckerberg. While there are plenty of concerns over Facebook's long-term value as an investment â¿¿ including the ability to monetize mobile use of the social network and Zuckerberg's controlling stake that could mean trouble if his interests conflict with those of other shareholders â¿¿ those were beyond the horizon Friday as the stock began trading. The solid, but not enormous, opening gain indicated a well-priced offering that balanced supply and demand. Before th first trade there was not much of a halo effect elsewhere in the social media space, lending credibility to pre-offering speculation that the Facebook IPO could draw in cash from other technology stocks in what has been a weak market for the past six weeks. Shares of LinkedIn managed a 2% gain early but surrendered the entire advance to be down 0.4% before the first Facebook trade, while key Facebook partner Zynga was actually down 4.3% and Groupon fell 1.6%. Google was up 0.5%, and the search giant's 2004 IPO and subsequent surge is an example many are citing as the closest precedent for the Facebook deal. Forbes' John Dobosz notes, however, that Google came public at a much lesser valuation than the social network that began trading Friday morning.